My neighbors and I used this R2 Solutions Moonlight 11000 MC, $30 (a little steep, but u get what u pay for), R2 Solutions Moonlight 11000 MC (Saltwater Aquarium Supplies > Lighting > Fixtures > Moon Lights )
It gives the tank the ripple & shimmer effect like MH
lights, except its blue and soothing. You can angle it make shadows on the rocks where the fish will hide, sleep, & the coral like it; Ive been told it helps them spawn? Bright enough to let you see the nightime critters, and there are a lot of them.